Belt tightener for machines for expanding metal



1931. J. H. DEAN ET AL ,514

BELT TIGH'I'ENER FOR MACHINES FOR EXPANDING METAL Filed March 5, 1926 [72 V672 2 oz"; .Z IMEJ/Z DEA/V GEO/P65 W54 KER Patented Jan. 6, 1931 UNITED STATES PATENT OFFICE JAMES H. DEAN, OF LUDIITGTON, MICHIGAN, AND GEORGE W. BAKER, OF CHICAGO,

ILLINOIS, ASSIGNORS, BY MESNE ASSIGNMENTS, T0 UNITED STATES GYPSUM COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS BELT TIG-I-ITENER FOR MACHINES FOR EXBANDING METAL 7 Application filed March 5, 1926." SerialNo. 92,539.

In Letters Patent issued April 6, 1909, No.

917,715, to Lewis E. Curtis, assignor, to Breckenridge Jones, trustee, there is shown and described a machine for expanding sheet metal which has been previously cut or slitted,

that employs diverging expander armswith feeding means, consisting of opposing chains in each arm, one above and one below the sheet, and moving with it and gripping its unexpanded margins, one of each pair of chains being arranged parallel to the line of feed, and the other one of each pair being arranged at an angle to such line.

In the operation of these machines the wear of the pivotal connections between the links causes the chains to become lengthened and loose upon their carrying and driving sprockets. The'looseness of the chains interferes with the proper feeding of the sheets. It has been attempted to remedy this by placing the sprocket atone end of each chain upon an eccentric hearing, but this means of tightening causes a separation of the opposing chains near their ends and this separation of the chains interferes with the proper feeding of the sheets.

Our improvement is designed to provide a satisfactory means for tightening the feeding chains of this Curtis machine without separating the opposing chains or otherwise interfering withtheir proper feeding function.

To this end our invention consists in the combination with the expander arm of a machine of the type indicated, of a pivoted arm.

carrying a roll or sprocket wheel arranged to engage the inner surface of the feeding belt at the non-feeding or idle side thereof,

and means for adjusting the'position of said Curtis machine of the type specified, with one of the side plates removed and with the parts'of the tightener device partly broken away;

Figure2 is line 2-2 of Figure 1; and

-Fig'ure 3 is 'a'transverse section on line 3-'-3 of Figure 1. j

In the drawing the reference numerals H indicate the side plates of'the expander arm,-said platesbeing connected by the bolts 5 and forming, with said connectingbolts, the frame of said arm. Oneof said plates 1s provided with alongitudinallyextending rib 6, against the edge'of which the other plate bears, said rib forming a spacing meansbetween said plates.' Mounted between said plates are the sprocket wheels 7 and 8 upon which the feeding chain 9 is mounted." These parts ofthe structure are all substantially as shown in the drawings of said Curtis Patent No.917,715. Arranged between said plates and mounted upon a fixed studor boltlO (see Figure 3) is an arm ll c arryin'g a roll'or sprocket wheel 12 mounted on a pin 2'O'and arranged to engagefthe inner surface of the chain 9. at the non-feed1ng or dle side thereof. Sa d arm 11 is recessed thereby forming a pair of short arms 13 projecting from the main part of the arm" and forming therewith a bell crank lever, pivotally supported on-the bolt 10, A threaded eye-bolt 14 pivoted between the arms, 13 upon a pin 15. The threaded portion of said bolt passes through cross-bar 16 pivotally supported, in the side plates 4 (see Figure 2). Nuts 17 arearranged-upon said threaded bolt on either side of said bar 16. l

In operation, as the connections of the belt become loose, the nuts17 upon the bolt 14 areadjusted so as tomove the roll or sprocket wheel'12jagainst theinner surface of-the belt to take up the slack or lost motion occasioned by the wear of the belt connections.- nuts maybe adjusted as often as found neces- 'sary to keep the feeding belt tight and in proper condition for feeding the metal sheets passing between the opposing surfaces of said belts. A sprocket wheel 12 or a detail horizontal section on These A a plain surfaced roll or wheel may be employed with substantially the same results.

'By placing the adjusting device within the belt and between the side plates 4-4 it is 5 practically sealed within theexpander arm and thus dirt or foreign material is prevented from accumulating thereon and interfering with the operation of said device.

The details of the construction maybe va 1O ried-without departing from our invention;

' We claim as our invention:

1. An expander arm comprising two side plates, sprocket wheels'between the plates having journals in the, plates, a chain con- 5 necting the sprocket wheels and having one run as a working element extending beyond the plates at one side, an arm pivotally supported by both plates and having a sprocket wheel engaging the non-working run of the 20 cha-inat the inner side, and means pivotally connected with said arm and adjustably mounted between the plates and runsof the Y sprocket wheel to move the arm, all chaintightening elements lying between the runs of the chain and being enclosed by the plates.

2. An expander armcomprising two side plates, a pair of sprockets arranged between the plates, and having journals in said plates, a chain connecting the sprockets and having 33 one run as a working element extending beyond the edgesof the plates, and means for tightening the chain, said means lying be; I tween the, runs of the chain, and'between the plates and being pivotally supported-by both V 35 of the plates, and including a'sprocket wheel "engaging the inner side or the non-working run of the chain. V V

3. An expander arm comprising two side plates a pair of sprocket wheels ournaled in and crosswise of the plates adjacent opposite ends thereof, a' chain connecting the sprocket wheels and having one run as a working element extending beyond the plates at one side, anvarm pivotally supported by 45 both plates, a sprocket wheel journaled upon the arm to engage the non-working run, a cross bar journaled by and between the plates and chain, a bolt loosely traversing the cross bar and ,pivotally connecte-dto thefarm adj-am cent the pivotal point offthe arm with the plates, the pivotal point of the bolt with the 7 arm lying intermediate the pivotal point of v the arm with the plates andthe non-working run. 7 r f In witness whereof we have hereunto set our hands this 11th da-yfof February, 1926.

1 r 7 JAMES H. DEAN.

- GEO. W. BAKER. 

